Can you give some clue about this?

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sijieshuai
Posts: 13
Joined: Tue May 14, 2013 1:51 pm

Can you give some clue about this?

Post by sijieshuai » Fri Mar 21, 2014 5:40 am

Today I got this assertion failed report information:

Assertion failed: (pointCount > 0), function b2ContactSolver, file /Users/shuaisijie/Documents/my_work_space/MyProjects/cocos2d-x-2.2/external/Box2D/Dynamics/Contacts/b2ContactSolver.cpp, line 71.

If you have ever seen this Assertion failed report, please tell me what may cause this, thx!

The function in b2ContactSolver.cpp and assertion failed position are below(assertion failed point at line 14 of the for loop):

Code: Select all

b2ContactSolver::b2ContactSolver(b2ContactSolverDef* def)
{
	m_step = def->step;
	m_allocator = def->allocator;
	m_count = def->count;
	m_positionConstraints = (b2ContactPositionConstraint*)m_allocator->Allocate(m_count * sizeof(b2ContactPositionConstraint));
	m_velocityConstraints = (b2ContactVelocityConstraint*)m_allocator->Allocate(m_count * sizeof(b2ContactVelocityConstraint));
	m_positions = def->positions;
	m_velocities = def->velocities;
	m_contacts = def->contacts;

	// Initialize position independent portions of the constraints.
	for (int32 i = 0; i < m_count; ++i)
	{
		b2Contact* contact = m_contacts[i];

		b2Fixture* fixtureA = contact->m_fixtureA;
		b2Fixture* fixtureB = contact->m_fixtureB;
		b2Shape* shapeA = fixtureA->GetShape();
		b2Shape* shapeB = fixtureB->GetShape();
		float32 radiusA = shapeA->m_radius;
		float32 radiusB = shapeB->m_radius;
		b2Body* bodyA = fixtureA->GetBody();
		b2Body* bodyB = fixtureB->GetBody();
		b2Manifold* manifold = contact->GetManifold();

		int32 pointCount = manifold->pointCount;
		b2Assert(pointCount > 0);// assertion failed here!!!!!!!!!!!!!!

		b2ContactVelocityConstraint* vc = m_velocityConstraints + i;
		vc->friction = contact->m_friction;
		vc->restitution = contact->m_restitution;
		vc->tangentSpeed = contact->m_tangentSpeed;
		vc->indexA = bodyA->m_islandIndex;
		vc->indexB = bodyB->m_islandIndex;
		vc->invMassA = bodyA->m_invMass;
		vc->invMassB = bodyB->m_invMass;
		vc->invIA = bodyA->m_invI;
		vc->invIB = bodyB->m_invI;
		vc->contactIndex = i;
		vc->pointCount = pointCount;
		vc->K.SetZero();
		vc->normalMass.SetZero();

		b2ContactPositionConstraint* pc = m_positionConstraints + i;
		pc->indexA = bodyA->m_islandIndex;
		pc->indexB = bodyB->m_islandIndex;
		pc->invMassA = bodyA->m_invMass;
		pc->invMassB = bodyB->m_invMass;
		pc->localCenterA = bodyA->m_sweep.localCenter;
		pc->localCenterB = bodyB->m_sweep.localCenter;
		pc->invIA = bodyA->m_invI;
		pc->invIB = bodyB->m_invI;
		pc->localNormal = manifold->localNormal;
		pc->localPoint = manifold->localPoint;
		pc->pointCount = pointCount;
		pc->radiusA = radiusA;
		pc->radiusB = radiusB;
		pc->type = manifold->type;

		for (int32 j = 0; j < pointCount; ++j)
		{
			b2ManifoldPoint* cp = manifold->points + j;
			b2VelocityConstraintPoint* vcp = vc->points + j;
	
			if (m_step.warmStarting)
			{
				vcp->normalImpulse = m_step.dtRatio * cp->normalImpulse;
				vcp->tangentImpulse = m_step.dtRatio * cp->tangentImpulse;
			}
			else
			{
				vcp->normalImpulse = 0.0f;
				vcp->tangentImpulse = 0.0f;
			}

			vcp->rA.SetZero();
			vcp->rB.SetZero();
			vcp->normalMass = 0.0f;
			vcp->tangentMass = 0.0f;
			vcp->velocityBias = 0.0f;

			pc->localPoints[j] = cp->localPoint;
		}
	}
}

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